Drive pinion for actuating a rapier rod in a weaving machine

Abstract

This invention is related to a drive pinion ( 1 ) for actuating a rapier rod ( 2 ) of a weaving machine, whereby interaction of rapier rod ( 2 ) with drive pinion ( 1 ) is subject to less hindrance and damage due to occurring impact load at increased operational speeds and/or larger weaving widths, in that the tooth thickness (Td) of at least one tooth ( 3 ) of the drive pinion ( 1 ) varies in widthwise-direction (Tb) of the tooth ( 3 ), and whereby this tooth thickness (Td) is larger in the middle area ( 5 ) than in the fringe areas ( 7 ).

1 . Drive pinion ( 1 ) for actuating a rapier rod ( 2 ) of a weaving machine, comprising a set of teeth ( 3 ) which are disposed in such a way that they engage a tooth profile ( 4 ) of a cooperating rapier rod ( 2 ), characterized in that the tooth thickness (Td) of at least one tooth ( 3 ) of the drive pinion ( 1 ) varies according to the widthwise-direction (Tb) of the tooth, and in that this tooth thickness (Td) is larger in the middle area ( 5 ) than it is in the fringe areas ( 7 ).  
   
   
       2 . Drive pinion ( 1 ) according to  claim 1 , characterized in that said tooth ( 3 ) is shaped as an involute.  
   
   
       3 . Drive pinion ( 1 ) according to  claim 1 , characterized in that tooth thickness progressively reduces from the middle area ( 5 ) on.  
   
   
       4 . Drive pinion ( 1 ) according to  claim 1 , characterized in that the shape of at least one of the tooth flanks ( 8 ) of a tooth ( 3 ) is shaped as a circular arc.  
   
   
       5 . Drive pinion ( 1 ) according to  claim 1 , characterized in that the shape of at least one of the tooth flanks ( 8 ) of a tooth ( 3 ) is shaped according to a logarithmic curve.  
   
   
       6 . Drive pinion ( 1 ) according to  claim 1 , characterized in that the difference between tooth thickness in the middle area (Tdm) and tooth thickness in the fringe areas (Tdr) is situated between 1 and 20% of tooth width (Tb).  
   
   
       7 . Drive pinion ( 1 ) according to  claim 1 , characterized in that the tooth shape of at least one tooth ( 3 ) of the drive pinion ( 1 ) symmetrically covers both sides of the middle area ( 5 ).  
   
   
       8 . Rapier device for a weaving machine, including a rapier rod ( 2 ) actuated by a drive pinion ( 1 ), characterized in that it concerns a drive pinion ( 1 ) in the embodiment of  claim 1 .  
   
   
       9 . Rapier weaving machine, characterized in that the said rapier weaving machine is equipped with one or more rapier devices according to  claim 8.